In recent years, electronic devices have become lighter and lighter in weight. This allows carrying and using an electronic device that includes a display, such as a portable phone and a mobile PC, in a public area. However, there arises a problem that confidential documents and information for personal use may be observed by a person nearby.
In view of the circumstances, there is suggested a display apparatus that allows switching a viewing-angle control mode. Specifically, the display apparatus is normally set at a wide viewing-angle display mode, and is switched to a narrow viewing-angle mode when used in a public area. The wide viewing-angle mode allows observing a displayed image from all directions. On the other hand, the narrow viewing-angle mode (i) allows observing a displayed image, in a normal way, from the front of the display where a user is, but (ii) makes it difficult to observe the displayed image from an oblique direction (alternatively, a solid image or a different image is seen). Furthermore, it is allowed to switch to a wide viewing-angle display mode so that the display apparatus can accommodate a demand for a wide viewing-angle in a situation where, for example, a number of people desire to see a picturized image.
In order to realize such displaying, there is suggested a structure that, for example, a display apparatus is segmented into several sections, and the respective sections are differentiated in an alignment direction, and the like, of liquid crystal. As such, in the case where the display is observed from a direction other than the front during the narrow viewing-angle mode, an image that is different from what is actually displayed on the display is observed. For example, Japanese Unexamined Patent Publication No. 2001-264768 (published on Sep. 26, 2001) (the publication will be referred to as Patent Document 1 hereinafter (corresponding U.S. applications to the publication include: U.S. Application Publication No. 2001/015782 (published on Aug. 23, 2001)) teaches a liquid crystal display apparatus with alignment layers that (i) sandwich a liquid crystal layer and (ii) are segmented into a plurality of regions, and adjacent regions are different from each other in an orientation direction.
Further, Japanese Unexamined Patent Publication No. 2001-318374 (published on Nov. 16, 2001) (the publication will be referred to as Patent Document 2 hereinafter (corresponding U.S. application to the publication includes U.S. Unexamined Patent Publication No. 2004/0100598, published on May 27, 2004)) teaches a display apparatus that allows switching an image display status and a mirror state.
The structure of Patent Document 1, however, is not adequate for making it difficult to observe a displayed image from an oblique direction (from a side).
Specifically, in the structure, alignment directions in adjacent liquid crystal layers are differentiated from each other so that (i) a region is made to be a light-shielding region (black display) and (ii) an adjacent region thereto is made to be a transmissive region. However, with this structure, the light-shielding region becomes dark, and therefore the transmissive region of displayed image (displayed information) is enhanced. In other words, it is easy to see an image and/or information that is displayed on the display apparatus. The structure of Patent Document 1, therefore, is not adequate for preventing a person from peeking the displayed image from an oblique direction.
Furthermore, neither of Patent Documents 1 and 2 teaches switching a viewing-angle control function and a mirror function. No display apparatus that allows switching a viewing-angle control function and a mirror function has been known.